Petri dish



FIG. 1 is the front perspective view showing my new design;

FIG. 2 is the front view thereof;

FIG. 3 is the left hand view thereof;

FIG. 4 is the top view thereof;

FIG. 5 is the rear view thereof;

FIG. 6 is the right hand view thereof; and,

FIG. 7 is the bottom view thereof. 

The ornamental design for a "petri dish," as shown and described. 